Torque transmission device

ABSTRACT

The invention concerns a torque transmission device in the drive train of a motor vehicle to transmit torque between a drive unit, especially an internal combustion engine, with a drive shaft, especially a crankshaft, and a transmission with at least two transmission input shafts that are tightly connected to a clutch disc having a friction lining, and there is an intermediate pressure plate between the friction lining of one clutch disc and the friction lining of the other clutch disc that is tightly connected to the drive shaft of the drive unit, whereby the friction lining of the clutch discs are between the intermediate pressure plate and the pressure plates that move axially with the assistance of an actuation device relative to the intermediate pressure plate in reference to the transmission input shafts in order to hold the friction linings between the intermediate pressure plate and the pressure plates. To enhance the bearing of the double clutch, the intermediate pressure plate is radially mounted on one of two transmission input shafts.

The invention concerns a torque transmission device in the drive train of a motor vehicle to transmit torque between a drive unit, especially an internal combustion engine, with a drive shaft, especially a crankshaft, and a transmission with at least two transmission input shafts that are tightly connected to a clutch disc having a friction lining, and there is an intermediate pressure plate between the friction linings of one clutch disc and the friction linings of the other clutch disc that is tightly connected to the drive shaft of the drive unit, whereby the friction lining of the clutch discs are between the intermediate pressure plate and the pressure plates that move axially with the assistance of an actuation device relative to the intermediate pressure plate in reference to the transmission input shafts in order to hold the friction linings between the intermediate pressure plate and the pressure plates.

The two clutch disks and the interacting pressure plates form a double clutch. In conventional torque transmission devices with a double clutch, the double clutch bearing system is frequently complicated.

The task of the invention is to create a torque transmission device according to the preamble of claim 1 by means of which the double clutch bearing system is improved.

The task is solved in that the intermediate plate is radially mounted on at least one of the transmission input shafts of a torque transmission device in the drive train of a motor vehicle to transmit torque between a drive unit, especially an internal combustion engine, with a drive shaft, especially a crankshaft, and a transmission with at least two transmission input shafts that are tightly connected to a clutch disc having a friction lining, and there is an intermediate pressure plate between the friction lining of one clutch disc and the friction lining of the other clutch disc that is tightly connected to the drive shaft of the drive unit, whereby the friction lining of the clutch discs are between the intermediate pressure plate and the pressure plates that move axially with the assistance of an actuation device relative to the intermediate pressure plate in reference to the transmission input shafts in order to hold the friction linings between the intermediate pressure plate and the pressure plates. This creates a rigid and compact bearing system for the double clutch. The intermediate pressure plate can be directly or indirectly mounted on one of the transmission input shafts, for example via an essentially tubular hub.

One preferred exemplary embodiment of the torque transmission device is characterized in that the intermediate pressure plate is mounted on one of the transmission input shafts with the assistance of a bearing device (especially a radial bearing) especially on an internally hollow transmission input shaft in which an additional transmission input shaft is rotatably mounted. The bearing can for example be a rolling bearing or a journal bearing.

Another preferred exemplary embodiment of the torque transmission device is characterized in that one of the clutch discs is releasably affixed (i.e., removable without destroying it) to one of the transmission input shafts, especially on the additional transmission input shaft. The bearing for the intermediate pressure plate is for example a support bearing that is shoved onto a bearing seat on the hollow transmission input shaft during assembly of the double clutch and is axially fixed with a snap ring. Then one of the clutch discs is affixed to the additional gear input shaft.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the clutch disc affixed to one of the transmission input shafts, especially to the additional transmission input shaft, has a two-part design. The motor-side clutch disc affixed to the additional transmission input shaft prevents access to the snap ring. The two-part design makes it easier to access the bearing of the intermediate pressure plate.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the clutch disc affixed to one of the transmission input shafts, especially to the additional transmission input shaft, has a hub from which an inner flanged ring proceeds that is releasably affixed, i.e., removable without destroying it, to an outer flanged ring on which the friction linings are mounted radially to the outside. The radial outside flanged ring is preferably installed in the double clutch on the transmission side during assembly. The radial inner flanged ring with the hub is loosely placed on the double clutch and only mounted after affixing the snap ring.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the two flanged rings are connected by at least one screw connection. The two flanged parts are advantageously centered by means of a centering seat. The two flanged rings can for example be keyed with each other via splines. For example, the two flanged parts or flanged rings are releasably connected by at least one snap connection.

Another preferred exemplary embodiment of the torque transmission device is characterized in that one of the gear input shafts is designed as a hollow shaft in which the additional transmission input shaft is rotatably mounted, whereby an essentially tubular hub is rotatably mounted between the two transmission input shafts with a drive-side and a transmission-side end, and the intermediate pressure plate is affixed to the drive-side of the hub. It is preferably affixed by rivets. The intermediate pressure plate can also be affixed to the hub by flanging or with a centering seat with a snap ring.

Other preferred exemplary embodiments of the torque transmission device are characterized in that the gear-side end of the hub within the hollow shaft is mounted in the hollow shaft, on the hollow shaft or on the additional transmission input shaft. The bearing can be a rolling bearing, preferably a needle bearing, or a journal bearing. For lubrication, the bearing can be connected with the oil chamber of the transmission, or with its own independently sealed grease lubrication system. The rigidity of the bearing is preferably such that the natural relaxation vibration of the of the first order lies above the driving mode.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the intermediate pressure plate is supported in an axial direction on one of the transmission input shafts. The axial control forces of the double clutch are thereby no longer transmitted to the crankshaft.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the double clutch is pre-mounted in a clutch housing. The clutch housing is also termed the bell housing. The accessibility of the pre-mounting points is for example enabled by corresponding accesses in the drive-side clutch disc of the double clutch.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the bearing site of the pre-mounted double clutch is around or close to the center of gravity of the double clutch. This arrangement of the bearing site or bearing device of the intermediate pressure plate makes it easier to mount and transport the pre-mounted double clutch.

Another preferred exemplary embodiment of the torque transmission device is characterized in that one of the transmission input shafts is designed as a hollow shaft in which the additional transmission input shaft is rotatably mounted, whereby the intermediate pressure plate is mounted via a bearing device directly on one of the transmission input shafts, especially the additional transmission input shaft. An additional pilot bearing can be provided for the additional transmission input shaft in the drive shaft on the drive-side end of the additional transmission input shaft.

Another preferred exemplary embodiment of the torque transmission device is characterized in that one of the transmission input shafts is designed as a hollow shaft in which the additional transmission input shaft is rotatably mounted, whereby the intermediate pressure plate is mounted via a bearing device to a hub bearing that is a releasably affixed, i.e. removable without destroying it, to the drive-side end of the additional transmission input shaft. The hub bearing is affixed for example using a screw that is screwed into a corresponding threaded hole in the drive-side end of the additional transmission input shaft.

Another preferred exemplary embodiment of the torque transmission device is characterized in that one of the clutch discs is tightly connected to the hub bearing. The hub bearing enables both clutch discs to have the same hub geometry. An additional pilot bearing can be provided for the additional transmission input shaft in the drive shaft on the drive-side end of the hub bearing.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the bearing device comprises a bearing outer race that is radially affixed to the inside of the intermediate pressure plate, and/or a bearing inner race that is radially affixed to the outside of the associated bearing input shaft. The bearing device is preferably designed as an angular contact ball bearing, for example an annular ball bearing. The bearing outer race can also be integrated in the intermediate pressure plate. Rolling bearings are disposed between the bearing outer race and bearing inner race in a familiar manner.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the bearing inner race has a bearing section that is shoved radially inward onto one of the transmission input shafts so that the transmission-side end of the bearing section lies on a step formed on the associated transmission input shaft. The bearing section essentially has the same shape as a circular cylinder jacket. Radially to the outside, the bearing section forms a contact surface for the rolling bearings of the bearing device. Instead of the step, a snap ring can be axially affixed to the associated transmission input shaft.

Another preferred exemplary embodiment of the torque transmission device is characterized in that an attachment section proceeds from the drive-side end of the bearing section to which a retaining ring is releasably affixed (i.e., removable without destroying it). The attachment section essentially extends in a radial direction. The retention ring is preferably affixed by means of at least one screw connection to the attachment section.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the retention ring is fixed with the aid of a screw connection to the attachment section of the bearing inner race. The screw connection is accessible during assembly, for example through a corresponding opening in the associated drive-side clutch disc.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the retention ring has a fixing section radially on the inside that exerts a closing force on the locking ring depending on the status of the screw connection, and the force causes the locking ring to engage in an annular groove that is provided in the associated transmission input shaft. This makes it easy to axially affix the bearing device on the associated transmission input shaft.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the locking ring is slotted and pretensioned so that it can be shoved onto the associated transmission input shaft. Only when the screw is tight is the pretension of the locking ring overcome so that it is axially fixed in the annular groove.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the bearing outer race, the bearing inner race, the retention ring and/or the locking ring are made of sheet metal. This can reduce manufacturing costs.

Another preferred exemplary embodiment of the torque transmission device is characterized in that there is a torsional vibration damper between the drive shaft of the drive unit and the double clutch, especially a dual-mass fly wheel comprising a damper input part that is firmly affixed to the drive shaft of the drive unit, and a damper output part that is releasably attached (i.e., removable without destroying it) to a double clutch housing part to which the intermediate pressure plate is affixed. The releasable connection is preferably a keyed axial plug-in connection, especially with complementary splines. The input part of the vibration damper is centered on the crankshaft. The double clutch is centered on one of the transmission shafts. Any offset in a radial direction can be at the contact site between the output part of the vibration damper and the energy storage mechanisms, especially bow springs of the vibration damper. The plug-in connection preferably designed as spline toothing ensures sufficient axial mobility of the double clutch relative to the vibration damper. This makes assembly easier. The primary parts or input parts of the vibration damper can be pre-mounted on the crankshaft. In addition, axial vibrations of the crankshaft that arise during operation are not transmitted to the clutch.

Another preferred exemplary embodiment of the torque transmission device is characterized in that there is a spring device between the double clutch housing part and the damper output part; the spring device presses the damper output part against a friction/sliding device that is between the damper input part and the damper output part. The spring device is preferably a diaphragm spring. The friction/sliding device is either attached to the damper input part, or the damper output part.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the damper output part has a recess to receive a section of the double clutch housing part on its inside radially within the friction/sliding device. This produces a stable, non-rotating connection between the parts connected by the plug-in connection.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the double clutch housing part is made of sheet metal and has a flanged area that serves to fasten the double clutch housing part to the intermediate pressure plate. The flanged area preferably has several feet with through-holes for fasteners such as screws or rivets.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the double clutch housing part has an external spline section that is designed as a single piece with the flanged area and is complementary to an internal spline that extend radially inward on the damper output part. The complementary splines easily create a nonrotating plug-in connection between the double clutch housing part and the output part of the vibration damper.

Another preferred embodiment of the torque transmission device is characterized in that the section with the external spline lies between the inner diameter and the outer diameter of the friction lining of the neighboring clutch disc. This arrangement has proven to be advantageous within the framework of the present invention.

Another preferred embodiment of the torque transmission device is characterized in that there is a reinforcing edge on the double clutch housing part radially within the external spline area. Inner reinforcement can be alternately provided by inserting another part.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the damper output part is essentially shaped like an annular disc made of sheet metal on which there is a radial internal spline and at least one radial outside catch finger or arm that engages in an energy storage mechanism of the vibration damper. The internal spline can be continuous. The internal spline can also have sections without teeth to provide peripheral reinforcement and improve the deformation behavior of the double clutch housing part. The damper output part can consist of one or a plurality of parts.

Another preferred exemplary embodiment of the torque transmission device is characterized in that two catch fingers or catch arms are diametrically opposed radially on the outside of the damper output part. This ensures that the torsional vibration damper functions sufficiently.

Another preferred exemplary embodiment of the torque transmission device is characterized in that there are radial slots near the catch fingers in the damper output part. The slots serve to make the output part elastic. This makes it possible to pretension the connection between the damper output part and the double clutch housing part when assembled.

Additional advantages, features and details of the invention are found in the following description in which various exemplary embodiments are described in detail with reference to the drawings. The features cited in the claims and in the description may be essential to the invention by themselves or in any combination thereof. The following is shown in the drawings:

FIG. 1 A lengthwise section of a torque transmission device with a two-part clutch disk;

FIG. 2 The torque transmission device from FIG. 1 during assembly of the two-part clutch disc;

FIG. 3 The torque transmission device from FIG. 1 before installing a torsional vibration damper;

FIG. 4 A lengthwise section of a torque transmission device with a so-called on-tube bearing;

FIG. 5 A lengthwise section of a torque transmission device with a so-called in-tube bearing;

FIG. 6 A lengthwise section of a torque transmission device with an intermediate pressure plate axially abutting one of the transmission input shafts during assembly;

FIG. 7 A similar torque transmission device as in FIG. 6 when assembled;

FIG. 8 A similar depiction as in FIG. 7, whereby the intermediate pressure plate is mounted on a transmission hollow shaft;

FIG. 9 Another exemplary embodiment in which the intermediate pressure plate is mounted on a hub bearing that is attached to the end of one of the transmission input shafts;

FIG. 10 Another exemplary embodiment in which the bearing of the intermediate pressure plate is offset from the drive;

FIG. 11 An enlarged section from FIG. 8;

FIG. 12 A perspective view of a damper output part that can be shoved onto a coupling housing part;

FIG. 13 An enlarged section from FIG. 12;

FIG. 14 A plan view of a damper output part according to another exemplary embodiment;

FIG. 15 A slotted variation of a damper output part;

FIG. 16 A two-part design of a damper output part, and

FIG. 17 A torque transmission device according to another exemplary embodiment in which the clutch discs of the double clutch are coupled via a separate damper to the associated transmission input shaft.

FIG. 1 shows a part of a drive train 1 of a motor vehicle. A double clutch 6 is between a drive unit 3, especially an internal combustion engine, from which a crankshaft 4 proceeds, and a transmission 5. There is a vibration damper 8 between the drive unit 3 and the double clutch 6. The vibration damper 8 is a dual-mass flywheel.

The crankshaft 4 of the internal combustion engine 3 is tightly connected via screw connections 9, 10 to an input part 11 of the torsional vibration damper 8. The input part 11 of the torsional vibration damper 8 is essentially shaped like a radially-extending annular disc that forms a vibration damper cage radially to the outside. A starter ring gear 12 is attached radially to the outside of the input part 11. At least one energy storage mechanism, especially a spring device 16, is at least partially held by the vibration damper cage. An output part 18 of the vibration damper 8 engages in the spring device 16. A slide ring/friction ring 19 is in between the input part 11 and the output part 18, and the ring is affixed to the input part 11. Between the output part 18 and a clutch housing part 22, is a pretensioned diaphragm spring 20 to press the output part 18 of the torsional vibration damper 8 against the slide ring/friction ring 19.

Radially to the inside, the output part 18 of the torsional vibration damper 8 is releasably attached (i.e. can be removed without being destroyed) to the clutch housing part 22. An intermediate pressure plate 26 is affixed to the clutch housing part 22 with the aid of rivets, of which only one rivet connection 24 can be seen in the sectional view. On the drive side, friction linings 29 of a first clutch disc 31 can be clamped between the intermediate pressure plate 26 and a pressure plate 28. The first clutch disc 31 is tightly held via a hub 33 to a first transmission input shaft 35 that is designed as a solid shaft. The first in transmission input shaft 35 is rotatably mounted in a second transmission input shaft 36 that is designed as a hollow shaft. A hub 38 is rotatably mounted on the drive-side end of the second transmission input shaft 36 with the aid of a rolling bearing 37, and the intermediate pressure plate 26 is radially affixed to the outside of the hub. On the transmission side, friction linings 40 of a second clutch disc 42 can be clamped between the intermediate pressure plate 26 and a pressure plate 39. The second clutch disc 42 is firmly connected via a hub 43 to a second transmission input shaft 36.

The double clutch 6 has a clutch housing 44 to which the pressure plates 28, 39 are mounted to prevent rotation but enable axial movement. In addition, the intermediate pressure plate 26 is affixed to the clutch housing 44. The clutch housing 44 is connected to the crankshaft 4 via the clutch housing part 22 and the torsional vibration damper 8. The double clutch 6 is actuated in a familiar matter via the actuation devices 46, 47 that interact with actuating levers 48, 49.

FIG. 2 shows the double clutch 6 during assembly. The second clutch disc 42 and hub 38 with the intermediate pressure plate 26 and rolling bearing 37 are pre-mounted on the transmission side. In addition, we can see in FIG. 2 that the first clutch disc 31 comprises an inner flanged ring 51 attached to the hub 32, and an outer flanged ring 52 attached to the friction linings 29. In FIG. 2, the friction linings 29 with the outer flanged ring 52 and the pressure plate 28 are pre-mounted on the drive side. The hub 33 with the inner flanged ring 51 of the first clutch disc 31 is not mounted. In this state, a snap ring 55 can be attached to axially affix the rolling bearing 37 to the transmission-side end of the second transmission input shaft 36. Then the hub 33 with the inner flanged ring can be attached to the outer flanged ring.

FIG. 3 shows the first clutch disc 31 in a mounted state. In the next assembly step, the clutch housing part 22 is connected to the output part 18 of the torsional vibration damper 8.

FIG. 4 shows a part of a drive train 61 of an automobile. A double clutch 66 is between a drive unit 63 (especially an internal combustion engine) from which a crankshaft 64 proceeds, and a transmission 65. The crankshaft 64 of the internal combustion engine 63 is tightly connected via screw connections 68 to a so-called flex plate 70. Radially to the outside, a starter ring gear 71 is attached to the flex plate 70. Several vanes 72 proceeding from the driven plate 73 are attached to the starter ring gear 71. The driven plate 73 is tightly connected to the crankshaft 64. Screw connections 75 affix an intermediate pressure plate 78 and a clutch housing part 79 radially to the outside of to the driven plate 73.

On the drive side, friction linings 89 of a first clutch disc 91 can be clamped between the intermediate pressure plate 78 and a pressure plate 88. The first clutch disc 91 with an intermediate torsional vibration damper 92 is coupled to a hub 93 that is tightly connected to a first gear box input shaft 95. The first transmission input shaft 95 is designed as a solid shaft and is rotatably mounted in a second transmission input shaft 96 that is designed as a hollow shaft.

A tubular hub 98 is rotatably mounted on the first transmission input shaft 95 by means of a needle bearing 97. The tubular hub 98 is between the two transmission input shafts 95 and 96. On the drive side, the tubular hub 98 has a conically expanding area to which the intermediate pressure plate 78 is radially affixed on the outside by means of rivets 99.

On the transmission side, friction linings 101 of a second clutch disc 102 can be held between the intermediate pressure plate 78 and a pressure plate 100. The second clutch disc 102 is coupled via a torsional vibration damper 103 to a hub 104 that is tightly connected to the second gear box input shaft 96.

The two pressure plates 88 and 100 can move axially in a familiar matter with the aid of actuating devices 106, 107 and actuating levers 108, 109 relative to the intermediate pressure plate 78. The crankshaft 64 transfers torque to and is born by double clutch 66 via the driven plate 73 and the flex plate 70. The tubular hub 98 is disposed radially between the two transmission input shafts 95 and 96 of the double clutch gear box.

The exemplary embodiment shown in FIG. 5 shows a similar torque transmission device as in FIG. 4. The same reference numbers are used to designate the same parts. To avoid repetition, we refer to the prior description of FIG. 4. The following will discuss the differences between the two exemplary embodiments.

In the exemplary embodiment shown in FIG. 4, the tubular hub 98 is mounted on the solid shaft 95. In the exemplary embodiment shown in FIG. 5, the tubular hub 98 is mounted in the hollow shaft 96 with the aid of a needle bearing 117.

In the exemplary embodiment in FIGS. 1 to 5, the engagement force braces against the crankshaft when the double clutch is actuated. To increase the rigidity, the driven plate 73 in the exemplary embodiments in FIGS. 4 and 5 is preferably designed with conical surfaces and has air holes to ensure that the double clutch 66 is cooled well. To increase rigidity, the tubular hub 98 has a conical area in the transition section of the intermediate plate 78. The tubular hub 98 can be made of an inductively hardened or appropriate deep drawn sheet-metal part, or a corresponding forged part.

FIG. 6 shows a lengthwise section of a torque transmitting device that is also termed a clutch assembly 140. The clutch assembly 140 comprises a double clutch 150 that connects a driving shaft 151, especially a crankshaft of an automobile engine, with two drivable shafts 152, 153, especially transmission input shafts, and can be separated from them. The double clutch 150 is connectable via a vibration damper 154 to the automobile engine, also termed an internal combustion engine. The torsional vibration fed by the crankshaft 151 to the damper 154 is at least basically filtered so that it is at least not completely transferred to the double clutch 150 or the transmission shafts 152, 153.

In regard to the basic design and function of the damper 154 that in this instance is a component of the so-called dual-mass flywheel or forms a dual-mass flywheel, we refer to DE OS 197 28 422, DE OS 195 22 718, DE OS 41 22 333, DE OS 41 17 582 and DE-OS 41 17 579. The damper 154 possesses an input part 155 that is tightly connected via radial inner sections to the crankshaft 151, for example by means of screws 156. The input part 155 is formed by a shaped sheet-metal part that bears another component 157 radially on the outside which is also a shaped sheet-metal part in this instance. The two components 155 and 157 border an annular chamber 158 in which are held at least the energy storage mechanisms (helical springs 159 in this instance) of at least one damper. The chamber 158 is preferably sealed at least radially to the outside and contains at least a small quantity of a viscous medium that preferably is a lubricant. The torque introduced by the crankshaft 151 into the clutch assembly 140 is transferred via the input part 155, 157 to the energy storage mechanism 159 and conducted from there via an output part 160 also engaging the energy storage mechanisms 159 to the double clutch 150. The output part 160 is formed by a flange-like component that radially engages in the inside of the chamber and interacts via arms or fingers 161 with the end areas of the energy storage mechanisms 159.

A slide ring/friction ring 163 is between the input part 155 and the output part 160, and the ring is affixed to the input part 155. Between the output part 160 and the component 157, there is a pretensioned diaphragm spring 164 so that the output part 160 of the torsional vibration damper 154 is pressed against the slide ring/friction ring 163.

Radially to the inside, the output part 160 of the torsional vibration damper 154 is equipped with an internal spline 166. The internal spline 166 of the output part 160 is complementary with the external spline 167 that is on a clutch housing part 168. The spline is designed so that the torsional vibration damper 154 with the output part 160 can be shoved onto the coupling housing part 168 in an axial direction. The coupling housing part 168 is connected to an intermediate pressure plate 170 by the connections 169, of which only one rivet connection is shown in the sectional view in FIG. 6. The intermediate pressure plate 170 interacts with pressure plates 171, 172 that are provided on the transmission side and drive side. Friction linings 173 that are attached radially on the outside to a first clutch disc 174 are between the intermediate pressure plate 170 and the pressure plate 172. The first clutch disc 174 is attached radially on the inside to a hub 175 that is firmly fixed to the drive shaft 152 and is designed as a solid shaft.

The solid shaft 172 that is also termed the first transmission input shaft is rotatably mounted in the second transmission input shaft 153 designed as a hollow shaft. A hub 178 to which a second to clutch disc 179 is attached radially on the outside is rotatably mounted on the drive-side end of the second transmission input shaft 153. Radially affixed to the outside of the second clutch disc 179 are friction linings 180 that can be clamped between the intermediate pressure plate 170 and the pressure plate 171.

The transmission shaft 152 designed as a solid shaft has a shaft section 181 between hub part 175 and hub part 178 on which a bearing device 183 is mounted for the intermediate pressure plate 170. The bearing device 183 comprises a bearing outer race 184 that is affixed radially on the inside of the intermediate pressure plate 170, and a bearing inner race 185 that lies radially on the outside of shaft section 181. Rolling bodies 186 in the form of balls or rollers are between the bearing inner race 185 and the bearing outer race 184. The bearing inner race 185 is axially fixed by snap rings 188, 189 that fit in corresponding grooves of the solid shaft 152. The snap ring 189 is slotted and is also termed a locking ring. A retention ring 191 is radially affixed to the outside of the bearing inner race 185 by a screw 190; the retention ring holds the locking ring 189 in an associated ring groove in the solid shaft 152.

FIG. 6 shows a pre-mounted clutch assembly 140. The torsional vibration damper 154 that is also termed a dual-mass flywheel is pre-mounted on the crankshaft 158. The double clutch 150 is pre-mounted on the transmission input shaft 152 with the aid of the bearing device 183. The hubs 175, 178 are tightly fixed to the respective transmission shafts 152, 153. During assembly, the bearing device 183 and especially the screw 190 for assembly and especially for axially fixing the bearing device 183 are accessible from the outside through an opening 192 in the first clutch disc 174. The bearing device 183 is axially fixed between the snap rings 188, 189 on the shaft section 181 of the transmission shaft 152 using the screw 190 and the retention ring 191. The flow of force is closed when the double clutch 150 is actuated given the axial bracing of the intermediate pressure plate 170 against the transmission shaft 152.

The transmission input shafts 152, 153 are equipped with helical teeth at the transmission side that enable the absorption of axial force. According to a feature of the invention, the output part 160 of the dual-mass flywheel 154 is not centered by an additional bearing. According to another feature of the invention, the bearing device 183 is at or near the center of gravity of the double clutch 150. This provides stable support for the double clutch 150 during transportation and assembly.

The double clutch 150 has a clutch housing 194 to which the intermediate pressure plate 170 is attached. The pressure plates 171, 172 are fixed to the clutch housing 194 in a manner that prevents rotation but allows axial movement. The clutch housing 194 can be tightly affixed to the crankshaft 151 by means of splines 166, 167. The double clutch 150 is actuated in a familiar matter via the actuation devices 196, 197 that interact with actuating levers 198, 199.

On the drive-side end of the transmission shaft 152, there is a bearing journal 201 that is received by a blind hole 204 in the transmission-side end of the crankshaft 151. A needle bearing 206 also termed a pilot bearing is in the blind hole 204.

FIG. 7 shows an assembled torque transmission device 140 similar to the one shown in FIG. 6. For reasons of clarity, not all parts are provided with reference numbers. When assembled, the output part 160 of the dual-mass flywheel 154 is tightly connected via its internal spline 166 to the outer spline 167 of the coupling housing part 168. The connection is also termed an axial plug-in connection 220. When mounting the transmission to the engine block, the connection of the double clutch 150 to the dual-mass flywheel 154 is made by the spline toothing 220. The output part 160 can also center the torsional vibration damper 154 (also termed the output flange) on the clutch housing part 168. A bearing, especially a radial bearing, is not necessary between the input part 155 and the output part 160 of the dual-mass flywheel 154. The spline toothing 220 allows an axial shift that enables vibrations to be decoupled. The bearing device 183 is positioned favorably in relation to the center of gravity of the double clutch 150. When the double clutch 150 is assembled, the bearing journal 201 of the transmission shaft 152 is born by the needle bearing 206 in the crankshaft 151. The bearing is also termed a pilot bearing and serves to improve the radial support of the clutch mass. The pilot bearing also reduces the radial offset of the transmission shaft 152 in relation to the crankshaft 151.

FIG. 8 shows a torque transmission device according to another exemplary embodiment. The same reference numbers are used to identify the same parts as were used in prior exemplary embodiments. For reasons of clarity, reference numbers not necessary for understanding are not included in FIG. 8. The following will discuss the differences between the individual exemplary embodiments.

In the exemplary embodiment in FIG. 8, the intermediate pressure plate is not on the first solid transmission shaft 152; instead, it is on the second hollow transmission shaft 153. The hollow transmission shaft 153 has a shaft section 221 on its drive-side end on which a bearing device 223 is mounted. The bearing device 223 has a bearing outer race 224 that is affixed to the intermediate pressure plate 170 radially to the inside. In addition, the bearing device 223 has a bearing inner race 225 that is radially on the outside of shaft section 221 of the hollow transmission shaft 153. Rolling bodies 226 are between the bearing inner race 225 and the bearing outer race 224.

On the transmission side, the bearing inner race 225 is axially fixed to a step 228 on the transmission shaft 153. On the drive side, the bearing inner ring 225 is fixed by a snap ring 229 that is also termed a locking ring and engages in a ring groove in the drive shaft 153. A retention ring 231 is radially affixed to the outside of the bearing inner race 225 by a screw 230; the retention ring holds the locking ring 229 in the ring groove in the transmission shaft 153.

The hollow transmission shaft 153 is preferably mounted directly in a transmission housing (not shown). It can therefore enhance axial clutch support to affix the double clutch on the hollow shaft 153. This reduces axial play.

FIG. 9 shows an exemplary embodiment that is similar to FIG. 6 and 7. The same reference numbers are used to identify the same parts. To avoid repetition, we refer to the prior description of FIG. 6 and 7. The following will only discuss the differences between the exemplary embodiments.

In the exemplary embodiment shown in FIG. 9, the clutch housing part 168 is drawn in further radially than in the prior exemplary embodiments. The internal spline 166 of the output part 160 of the torsional vibration damper 154 and the external spline 167 of the clutch housing part 168 are near the inner diameter of the friction linings 173, 180 of the double clutch 150.

In addition, the hub 175 in the exemplary embodiment in FIG. 9 is not directly mounted on the solid transmission shaft 152; rather, it is mounted on a hub bearing 235. In The hub bearing 235 has essentially the shape of a circular cylinder jacket section with the same outer diameter as the hollow transmission shaft 153. On the drive-side end of the hub bearing 235, there is a bearing sleeve 236 that has a smaller outer diameter than the hub bearing 235. With the aid of a needle bearing 237 that is also termed a pilot bearing, the bearing sleeve 236 is rotatably mounted in a retention element 238 that is affixed to the crankshaft 151 with the assistance of the screws 156.

The circular cylinder jacket section of the hub bearing 235 is also termed an attachment section 239. The attachment section 239 of the hub bearing 235 is connected radially on the outside of the hub 175 of the first clutch disc 174. The hub bearing 235 is affixed to the drive-side end of the solid transmission shaft 152 with a screw 241. The attachment section 239 of the hub bearing 235 has a step 242 on its transmission-side end. The step 242 axially fixes a bearing device 243 for the intermediate pressure plate 170 on the solid transmission shaft 152. The bearing device 243 comprises a bearing outer race 244 that is affixed to the intermediate pressure plate 170 radially to the inside. In addition, the bearing device 243 comprises a bearing inner race that is radially mounted on the outside of the transmission-side end of the hub bearing 235. The bearing inner race 245 axially abuts the step 242. Rolling bodies 245 are between the bearing inner race 244 and the bearing outer race 246.

The bearing device 243 can be pre-mounted and hence axially fixed on the hub bearing 235. While mounting the double clutch 150 in a bell housing 247, the hub bearing 235 is shoved onto the drive-side end of the solid transmission shaft 152. The screw 241 for axially fixing the hub bearing 235 to the solid transmission shaft 152 can be easily reached during assembly. The axial support for the coupling force is provided via the step 242 on the hub bearing 235.

The tight connection between hub 175 and hub bearing 235 also enables the transmission of torque between the clutch disc 174 and the solid transmission shaft 152. It is particularly advantageous that the two clutch discs 174, 179 can have the same hub geometry due to the outer diameter of the attachment section 239.

FIG. 10 shows an exemplary embodiment that is similar to FIG. 6 and 7. The same reference numbers are used to identify the same parts. To avoid repetition, we refer to the prior description of FIG. 6 and 7. The following will discuss the differences between the individual exemplary embodiments.

In the exemplary embodiment shown in FIG. 10, a clutch housing parts 248 is affixed to the intermediate pressure plate 170, and the clutch housing part extends further radially inward than in the prior exemplary embodiments. Radially to the outside, the clutch housing part 248 is affixed to the intermediate pressure plate 170 with rivets 249. At the pressure plate 172, the clutch housing part 248 is tightly fixed by the external spline 167 to the internal spline 166 of the damper output part 160. A connecting part 252 extends radially inward from the area of the clutch housing part 248 with the external spline 167. The radial inner end of the connecting part 252 abuts the solid transmission shaft 152 via a bearing device 253. The bearing device 253 includes a bearing outer race 254 and a bearing inner race 255. Rolling bodies 256 are between the bearing inner race 255 and the bearing outer race 254. The bearing outer race 254 is affixed to a retaining ring 257 that is axially fixed to the crankshaft 151 with the assistance of a snap ring 259 that is also termed a locking ring. On the side of the bearing device 255 facing the transmission, the hub 175 of the first clutch disc 174 is tightly affixed to the solid shaft 152. The bearing device 253 is on a shaft section 261 of the solid transmission shaft 152 that lies between the bearing journal 201 of the transmission shaft 152 and the hub 175.

In the exemplary embodiment shown in FIG. 10, the bearing device 253 is in front of the clutch disc hubs 175, 178 on the drive side. This makes axial fixation easier. The disadvantage of this arrangement is that the bearing device 253 is not optimally below the center of gravity of the double clutch 150.

In FIG. 11, the section with the bearing device 223 from FIG. 8 is enlarged. In FIG. 11, we see that the bearing inner race 255 has an essentially circular cylinder jacket bearing section 265 that is axially fixed between the step 228 and the locking ring 229 on the drive-side end of the hollow transmission shaft 153. An attachment section 267 extends outward essentially in a radial direction from the drive-side end of the bearing section 265. The retention ring 231 is affixed with a screw 230 to the attachment section 267 that is joined as a single piece to the bearing section 265. In FIG. 11, we see that the bearing device 223 consists of sheet metal parts. Before assembly, the screws 230, that are also termed locking screws, are loosened. This allows the retention ring 231 to move axially, and allows the pretensioned, slotted locking ring 229 to expand. When the double clutch with the bearing device 223 is shoved onto the hollow transmission shaft 153, then the locking screws 230 can be tightened through the openings 192 in the first clutch disc 174. The radially internally conical retention ring 231 compresses the locking ring 229 when the locking screws 230 are tightened so that the locking ring engages in the ring groove in the hollow transmission shaft 153. This fixes the double clutch in an axial direction. When disassembling, the locking screws 230 must be loosened. The locking ring 129 then opens due to its pretension. Depending on the design, snap hooks or a bayonet ring can be used instead of the locking ring 229 to axially fix the bearing device 223. However, it must be ensured that the corresponding mounting sites (such as the openings 192) remain accessible from the outside during assembly.

FIG. 12 shows a perspective view of a separated damper output part 160 with an internal spline 166 and a clutch housing part 168 with external spline 167 as in the torque transmission devices in FIG. 6 and 7. The damper output part 160 that is also termed a clutch flange, is designed as a sheet metal part. Radially to the outside, two diametrically opposed arms or fingers 161, 162 are on the damper output part 160. The internal spline 166 and the external spline 167 are provided with chamfers and roundings to assist assembly. The teeth are easily engaged during assembly given the high number of teeth and equivalent tooth shape over the entire perimeter. To leave a large amount of installation space for the clutch on the clutch side of the flange, the dual-mass flywheel flange 160 is narrow both axially and radially.

The clutch housing part 168 has a flanged area 281 on the transmission side that has several feet 282, 283, 284. There are several through-holes 286, 287, 288 in the feet for fasteners. The clutch housing part 168 has a reinforcing edge 290 radially on the inside. The reinforcing edge 290 serves to minimize undesired deformation of the external spline 167.

FIG. 13 shows an enlarged section from FIG. 12 where the internal spline 166 of the damper output part 160 is engaged with the external spline 167 of the clutch housing part 168. As can be seen in FIG. 13, the clutch housing part 168 can be axially inserted with its external spline into the damper input part 160.

FIGS. 14 to 16 show plan views of different exemplary embodiments of the damper output part 160. In all exemplary embodiments, two arms or fingers 161, 162 are diametrically opposed on the outside of the damper output part 160. In addition, the damper output part 160 is relatively thin in all three exemplary embodiments. When force is introduced through the bow springs of the dual-mass flywheel, there exists a tendency to bulge in a radial direction. By holding the damper output part 160 on the more rigid coupling housing part 168 (see FIG. 12) that is also termed the inner part, the extent of the deformation is kept within tolerable limits for the teeth.

In the exemplary embodiment shown in FIG. 14, the teeth 166 are not continuous; rather, there are also sections 294, 295 without teeth. The deformation behavior of the damper output part 160 can be enhanced by the sections 294, 295 without teeth.

In the exemplary embodiment in FIG. 15, radial inner slots 298, 299 are in the damper output part 160 near the arms 161, 162. The slots 298, 299 extend radially but are not continuous. The slots 298, 299 make the damper output part 160 elastic. A pretensioned variation of the spline toothing is thereby created without using additional parts. This can reduce wear and prevent noise.

FIG. 16 shows a damper output part 160 consisting of two halves 301, 302 that are elastically connected at connecting sites 304, 305. This improves the flow of force in the damper output part 160. In addition, it can reduce deformation while the damper output part 160 is operating. The multi-part design of the dual-mass flywheel also makes it particularly economical to manufacture. When for example two peripherally symmetrical halves 301, 302 are combined, the parts can be produced from sheet metal with little stamping wastes.

FIG. 17 shows an exemplary embodiment in which a double clutch 310 is coupled to a crankshaft 151 via a catch part 311. Radially to the inside, the catch part 311 is affixed to the crankshaft 151 by screws 312. Radially to the outside, the catch part 311 is affixed to a clutch housing part 315 by screws 314. An intermediate pressure plate 316 is affixed to the clutch housing part 315 (not shown). On the drive side, friction linings 318 of a first clutch disc 319 can be clamped between the intermediate pressure plate 316 and a pressure plate 317. The first clutch disc 319 is coupled to a hub 321 of the first clutch disc 319 via a vibration damper 320. The hub 321 is tightly fixed to a hub bearing 322 that is attached with a screw 323 to a transmission shaft 152 that is designed as a solid shaft.

On the transmission side, friction linings 326 of a second clutch disc 327 can be held between the intermediate pressure plate 316 and the pressure plate 325. The second clutch disc 327 is coupled to a hub 329 by another vibration damper 328, and the hub is tightly mounted to the drive-side end of a hollow transmission shaft 153.

The transmission-side end of the hub bearing 322 has a peripheral step 330 against which axially abuts a bearing device 333 for the intermediate pressure plate 316. The bearing device 333 comprises a bearing outer race 334 that is affixed to the intermediate pressure plate 316 radially to the inside. In addition, the bearing device 133 comprises a bearing inner race 135 that is radially mounted on the hub bearing 322. Rolling bodies 336 are between the bearing inner race 335 and the bearing outer race 334.

In the exemplary embodiment in FIG. 17, there is no two-mass flywheel in contrast to the prior exemplary embodiments. Given the substantial torque load, the connection between the double clutch 310 and the crankshaft 151 is not designed as a plug-in connection in this exemplary embodiment. The access to the screws 314 during assembly is indicated by an arrow 338. The double clutch 310 is connected to the crankshaft 151 via the catch plate 311 in the exemplary embodiment shown in FIG. 17.

In the exemplary embodiments shown in FIGS. 6 to 16, the actuating force of the double clutch is supported by the bearing device on one of the transmission input shafts. At the same time, the bearing device advantageously provides radial clutch support. The clutch can be pre-mounted in the bell housing. The two-mass flywheel can be pre-mounted on the crankshaft. The connection to the clutch is made in during assembly with spline toothing. The spline toothing axially decouples the clutch from the crankshaft vibration. The required radial compensation of the clutch in relation to the crankshaft is provided by the mobility of the damper output part in the two-mass flywheel. The damper output part with the internal spline is centered by the clutch housing part with the external spline, and it can be aligned at its contact sites with the parts of the two-mass flywheel. 

1. A torque transmission device for a drive train of a motor vehicle to transmit torque between a drive unit with a drive shaft, and a transmission with at least two transmission input shafts that are connected to a double clutch including first and second clutch discs each having a friction lining, and an intermediate pressure plate between the friction linings of the first clutch disc and the friction linings of the second clutch disc and connected to the drive shaft of the drive unit, whereby the friction linings of the clutch discs are between the intermediate pressure plate and pressure plates that move with the assistance of an actuation device in an axial direction relative to the intermediate pressure plate in reference to the transmission input shafts in order to hold the friction linings between the intermediate pressure plate and the pressure plates, wherein the intermediate plate is mounted on at least one of the transmission input shafts in a radial direction.
 2. A torque transmission device according to claim 1, wherein the intermediate pressure plate is mounted on one of the transmission input shafts with a radial bearing carried on an internally hollow transmission input shaft within which an additional transmission input shaft is rotatably mounted.
 3. A torque transmission device according to claim 2, wherein at least one of the clutch discs is releasably affixed to one of the transmission input shafts.
 4. A torque transmission device according to claim 3, wherein the clutch disc releasably affixed to one transmission input shaft has a two-part design.
 5. A torque transmission device according to claim 4, wherein the clutch disc releasably affixed to the one of the transmission input shaft includes a hub from which an inner flanged ring extends that is releasably affixed to an outer flanged ring on which the friction linings are radially outwardly mounted.
 6. A torque transmission device according to claim 5, wherein the flanged rings are connected by at least one screw connection.
 7. A torque transmission device according to claim 1, wherein one of the input shafts is a hollow shaft in which an inner transmission input shaft is rotatably mounted, whereby a tubular hub is rotatably mounted between the two transmission input shafts with a drive-side and a transmission-side end, and the intermediate pressure plate is affixed to the drive-side of the hub.
 8. A torque transmission device according to claim 7, wherein the transmission-side end of the hub is mounted in the hollow shaft.
 9. A torque transmission device according to claim 7, wherein the transmission-side end of the hub is mounted on the inner shaft.
 10. A torque transmission device according to claim 1, wherein the intermediate pressure plate is axially supported on one of the transmission input shafts.
 11. A torque transmission device according to claim 1, wherein the double clutch is pre-mounted in a clutch housing.
 12. A torque transmission device according to claim 11, the wherein a bearing site of the pre-mounted double clutch is around or close adjacent to the center of gravity of the double clutch.
 13. A torque transmission device according to claim 10, wherein one of the transmission input shafts a hollow shaft in which the inner transmission input shaft is rotatably mounted, whereby the intermediate pressure plate is mounted via a bearing device directly to one of the transmission input shafts.
 14. A torque transmission device according to claim 10, wherein one of the transmission input shafts is a hollow shaft in which an inner transmission input shaft is rotatably mounted, whereby the intermediate pressure plate is mounted via a pressure plate bearing to a hub bearing that is a releasably affixed to the drive-side end of the inner transmission input shaft.
 15. A torque transmission device according to claim 14, wherein one of the clutch discs is securely connected to the hub bearing.
 16. A torque transmission device according to claim 14, wherein the intermediate pressure plate bearing includes a bearing outer race that is radially affixed to the inside of the intermediate pressure plate, and an bearing inner race that is radially affixed externally of the associated transmission input shaft.
 17. A torque transmission device according to claim 16, wherein the bearing inner race includes a bearing section that is radially inward of one of the transmission input shafts so that a transmission-side end of the bearing section lies on a step formed on the associated transmission input shaft.
 18. A torque transmission device according to claim 17, wherein an attachment section extends from a drive-side end of the bearing section to which a retaining ring is releasably affixed.
 19. A torque transmission device according to claim 18, wherein the retaining ring is fixed with the aid of a screw connection to the attachment section of the bearing inner race.
 20. A torque transmission device according to claim 19, wherein the retaining ring has a radially inner fixing section that exerts a closing force on the retaining ring through the screw connection, and a screw connection force causes a locking ring to mesh in an annular groove that is provided in the associated transmission input shaft.
 21. A torque transmission device according to claim 20, characterized in that wherein the locking ring is slotted and pretensioned so that it can be inserted onto the associated transmission input shaft.
 22. A torque transmission device according to claim 20, wherein the bearing outer race, the bearing inner race, the retaining ring and the locking ring are formed from sheet metal.
 23. A torque transmission device according to claim 1, wherein a torsional vibration damper is positioned between the drive shaft of the drive unit and the double clutch, and includes a dual-mass fly wheel having a damper input part that is affixed to the drive shaft of the drive unit, and a damper output part that is releasably attached to a double clutch housing part to which the intermediate pressure plate is affixed.
 24. A torque transmission device according to claim 23, wherein a spring device is positioned between the double clutch housing part and the damper output part, and wherein the spring device presses the damper output part against a friction device that is positioned between the damper input part and the damper output part.
 25. A torque transmission device according to claim 24, wherein the damper output part includes a recess to receive a section of the double clutch housing part radially inwardly of the friction device.
 26. Torque A torque transmission device according to claim 23, wherein the double clutch housing part is made of sheet metal and includes a flange to fasten the double clutch housing part to the intermediate pressure plate.
 27. A torque transmission device according to claim 26, wherein the double clutch housing part includes an external spline section that is integral with the flange and is complementary to an internal spline that is radially inward on the damper output part.
 28. A torque transmission device according to claim 27, wherein the outer spline of the double clutch housing part lies radially between an inner diameter and an outer diameter of the friction linings of an adjacent clutch disc.
 29. A torque transmission device according to claim 27, including a reinforcing edge on the double clutch housing part radially within the external spline section.
 30. A torque transmission device according to claim 23, wherein the damper output part is substantially an annular disc made of sheet metal on which there is an inner radial spline and at least one catch finger for engagement with an energy storage mechanism of the vibration damper.
 31. A torque transmission device according to claim 30, wherein two radial catch fingers are diametrically opposed on the outside of the damper output part.
 32. A torque transmission device according to claim 31, including inner radial slots near adjacent to the catch finger fingers in the damper output part. 